This invention relates in general to methods for the separation of gas mixtures and, more particularly, to a method for the removal of H.sub.2 S from a gas mixture.
Much attention has been focused in recent years on the removal of H.sub.2 S from natural or synthetic fuel gases because of environmental concerns. Conventional methods for the removal of H.sub.2 S involve the use of aqueous or other types of scrubbers which are expensive to install, operate and maintain. After removal from the gas stream, the H.sub.2 S is recovered through thermal regeneration of the scrubbing liquor. The H.sub.2 S must then be sent to a Claus or other processing plant to obtain elemental sulfur through partial oxidation of the H.sub.2 S. These processes, however, are of limited efficiency and have high energy costs.
Electrochemical processes have been utilized for the removal of H.sub.2 S and sulfur oxides from high temperature gas streams using an electrolyte comprising molten alkali metal salts to transport sulfate and/or sulfide ions from a cathode to an electrode where they are oxidized and removed as gases. These processes, however, require operating temperatures in excess of the melting point of the alkali metal salt and have limited low temperature applications.